There is an increased mortality and rate of renal transplant rejection associated with the primary cytomegalovirus (CMV) infections routinely encountered by kidney transplant patients. Because there has been no effective means of prevention or treatment for CMV infection we propose a controlled trial to evaluate the prophylactic value of a novel cytomegalovirus hyperimmune globulin now available as a investigational product of the Massachusetts Biuologic Laboratories. The background incidence of CMV infection among transplant recipients in whom the trial would be carried out is 70% and the incidence of symptomatic CMV disease is approximately 50%. The CMV immune globulin (CF greater than or equal to 128, IHA greater than or equal to 4000 ELISA greater than or equal to 4000) has been prepared from normal donor plasma, selected onthe basis of ELISA tests for high titers of antibody to CMV. It has been formulated as an intravenous product (CMVIG-IV) so that large amounts of antibody can be easily infused. The expectation of clinical success is based on three observations: 1) recent studies in bone marrow transplant patients given intramuscular cytomegalovirus immune globulin, human (Massachusetts Biologic Laboratories) have shown that this preparation may prevent CMV infection, 2) studies in premature neonates at high risk of transfusion-acquired CMV infection have shown that neonates born to mothers with antibody to CMV have a significantly lower risk of CMV associated disease and mortality, 3) animal studies support the concept that exogenous CMV antibody attenuates CMV disease. For clinical relevance and efficiency of study design we will focus on kidney transplant recipients at highest risk of primary infection, i.e. lacking CMV antibody (titer less than 8 by IHA). Patients who receive CMV seropositive donor kidneys will be randomized to receive CMVIG-IV or no CMV specific prevention. All patients will be followed by obtaining serial blood, urine, and throat swab specimens for viarl isolation over the first 8 months post transplant. Additional examinations will be made upon clinical suspicion of CMV infection. We estimate that with a background incidence of 70%, 36 patients and 36 controls should be sufficient to test our hypothesis of an expected 50% reduction in CMV infections (alpha=0.05, beta=0.9) in the group receiving CMVIG-IV.